The present invention relates to a thermoplastic resin composition and interior or exterior parts for vehicles using thereof, which are excellent in flexibility, surface appearance, weatherability, moldability and heat deformation property and has low tackiness at a high temperature.
In recent years, a resin such as PVC, olefin or urethane is employed as a flexible resin in the field of an automobile, electric appliances for domestic use and OA apparatus, and the like. Among those, a flexible resin of PVC is widely employed as a flexible PVC. But a PVC flexible resin has a problem in weight loss at heating and migration of a plasticizer, since much plasticizer need to be added thereto. In a flexible resin other than PVC such as a flexible resin of styrene, a resin having a segment of isoprene, butadiene or the like was proposed. But it is on demerit especially in economy from the viewpoint of equipment and productivity, and has high tackiness at a high temperature, since it is a block copolymer of a hard segment and a soft segment and it need to be prepared by the particular polymerization method in a non-aqueous solvent. On the other hand an flexible resin of olefin is difficult to be applied and printed, and has a problem of a less surface modification property.
As to a resin of styrene, Japanese Unexamined Patent Publication No. 20346/1984 discloses a method of adding a particular plasticizer to a styrene resin reinforced by a rubber. But it is not sufficient because of volatilization of the plasticizer. As to a composition of an ABS resin and a copolymer of an acrylic ester, Japanese Unexamined Patent Publication No. 179257/1983 discloses a composition comprising a styrene resin containing a rubber and a copolymer of an acrylic ester copolymer, and Japanese Unexamined Patent Publication No. 17954/1988 discloses a composition comprising a copolymer of maleimide-styrene containing a rubber, an ABS resin and a copolymer of an acrylic ester copolymer. And it is described that a molded article of the composition is excellent in a chemical resistance. However, these compositions are remarkably lack in flexibility, the resin has not been obtained, which is excellent in flexibility, surface appearance, weatherability and heat deformation property at heating, and has low tackiness at a high temperature.
And Japanese Unexamined Patent Publication No. 27336/1996 discloses a composition comprising a maleimide-styrene copolymer containing a rubber and an acrylic ester copolymer. But the resin has not been obtained, which is excellent in flexibility as the composition of the present invention.
Many graft copolymers (rubber) of ABS resin (of which matrix is a copolymer of styrene and acrylonitrile or a copolymer of styrene, acrylonitrile and maleimide) have been proposed, but there has been proposed no graft copolymers (rubber), which is suitable to a resin comprising a copolymer of maleimide-styrene-acrylonitrile and a copolymer of an acrylic ester.
An object of the present invention is to provide a thermoplastic resin composition and interior or exterior parts for vehicles molded thereof, which has no problems mentioned-above, is excellent in flexibility, surface appearance, weatherability, moldability and heat deformation property, and has low tackiness at a high temperature.